The use of positive end expiratory pressure (PEEP) when ventilating patients in critical care is pretty universal, but it’s also true that we don’t entirely know how much to use and when. The rationale for PEEP is to prevent alveolar collapse (and possibly to take some role in recruiting areas already collapsed) and improve oxygenation. The costs of PEEP however are a rise in intrathoracic pressure (with the associated haemodynamic effects) and the risk of overdistension of lung units (leading to cytokine release etc.).

​The EDEN trial is one of the go-to trials for feeding in the ICU. The paper can be found here, but essentially it recruited 1000 patients with respiratory failure, comparing different calorie targets for a period of 6 days. One group received 25% of requirements (the trophic feeding group), with the other aiming for full requirements (receiving 80% of goal).* The primary outcome was ventilator free days to day 28, with the study powered to detect a 2.25 day difference. 60 day mortality was a secondary outcome.